define/Once|{ value }|
  let/call = 1
  return() {
    if (call) {
      call--;
      value();
    }
  }
let/clickOnceCount = 0;
Once/onClickOnce() {
  clickOnceCount++;
}
button.once onClick=onClickOnce -- ${clickOnceCount}

define/Twice|{ value }|
  let/call = 2
  return() {
    if (call) {
      call--;
      value();
    }
  }
let/clickTwiceCount = 0;
Twice/onClickTwice() {
  clickTwiceCount++;
}
button.twice onClick=onClickTwice -- ${clickTwiceCount}
